libguile/procprop.c

   1 /*      Copyright (C) 1995,1996,1998 Free Software Foundation, Inc.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2, or (at your option)
   6  * any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this software; see the file COPYING.  If not, write to
  15  * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  16  * Boston, MA 02111-1307 USA
  17  *
  18  * As a special exception, the Free Software Foundation gives permission
  19  * for additional uses of the text contained in its release of GUILE.
  20  *
  21  * The exception is that, if you link the GUILE library with other files
  22  * to produce an executable, this does not by itself cause the
  23  * resulting executable to be covered by the GNU General Public License.
  24  * Your use of that executable is in no way restricted on account of
  25  * linking the GUILE library code into it.
  26  *
  27  * This exception does not however invalidate any other reasons why
  28  * the executable file might be covered by the GNU General Public License.
  29  *
  30  * This exception applies only to the code released by the
  31  * Free Software Foundation under the name GUILE.  If you copy
  32  * code from other Free Software Foundation releases into a copy of
  33  * GUILE, as the General Public License permits, the exception does
  34  * not apply to the code that you add in this way.  To avoid misleading
  35  * anyone as to the status of such modified files, you must delete
  36  * this exception notice from them.
  37  *
  38  * If you write modifications of your own for GUILE, it is your choice
  39  * whether to permit this exception to apply to your modifications.
  40  * If you do not wish that, delete this exception notice.  */
  41
  42 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
  43    gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
  44
  45 \f
  46
  47 #include <stdio.h>
  48 #include "_scm.h"
  49
  50 #include "alist.h"
  51 #include "eval.h"
  52 #include "procs.h"
  53 #include "gsubr.h"
  54 #include "objects.h"
  55
  56 #include "scm_validate.h"
  57 #include "procprop.h"
  58 \f
  59
  60 SCM_GLOBAL_SYMBOL (scm_sym_system_procedure, "system-procedure");
  61 SCM_GLOBAL_SYMBOL (scm_sym_arity, "arity");
  62
  63 SCM
  64 scm_i_procedure_arity (SCM proc)
  65 {
  66   int a = 0, o = 0, r = 0;
  67   if (SCM_IMP (proc))
  68     return SCM_BOOL_F;
  69  loop:
  70   switch (SCM_TYP7 (proc))
  71     {
  72     case scm_tc7_subr_1o:
  73       o = 1;
  74     case scm_tc7_subr_0:
  75       break;
  76     case scm_tc7_subr_2o:
  77       o = 1;
  78     case scm_tc7_subr_1:
  79     case scm_tc7_cxr:
  80     case scm_tc7_contin:
  81       a += 1;
  82       break;
  83     case scm_tc7_subr_2:
  84       a += 2;
  85       break;
  86     case scm_tc7_subr_3:
  87       a += 3;
  88       break;
  89     case scm_tc7_asubr:
  90     case scm_tc7_rpsubr:
  91     case scm_tc7_lsubr:
  92       r = 1;
  93       break;
  94     case scm_tc7_lsubr_2:
  95       a += 2;
  96       r = 1;
  97       break;
  98 #ifdef CCLO
  99     case scm_tc7_cclo:
 100       if (SCM_CCLO_SUBR (proc) == scm_f_gsubr_apply)
 101         {
 102           int type = SCM_INUM (SCM_GSUBR_TYPE (proc));
 103           a += SCM_GSUBR_REQ (type);
 104           o = SCM_GSUBR_OPT (type);
 105           r = SCM_GSUBR_REST (type);
 106           break;
 107         }
 108       proc = SCM_CCLO_SUBR (proc);
 109       a -= 1;
 110       goto loop;
 111 #endif
 112     case scm_tc7_pws:
 113       proc = SCM_PROCEDURE (proc);
 114       goto loop;
 115     case scm_tcs_closures:
 116       proc = SCM_CAR (SCM_CODE (proc));
 117       if (SCM_IMP (proc))
 118         break;
 119       while (SCM_CONSP (proc))
 120         {
 121           ++a;
 122           proc = SCM_CDR (proc);
 123         }
 124       if (SCM_NIMP (proc))
 125         r = 1;
 126       break;
 127     case scm_tcs_cons_gloc:
 128       if (SCM_OBJ_CLASS_FLAGS (proc) & SCM_CLASSF_PURE_GENERIC)
 129         {
 130           r = 1;
 131           break;
 132         }
 133       else if (!SCM_I_OPERATORP (proc))
 134         return SCM_BOOL_F;
 135       proc = (SCM_I_ENTITYP (proc)
 136               ? SCM_ENTITY_PROCEDURE (proc)
 137               : SCM_OPERATOR_PROCEDURE (proc));
 138       a -= 1;
 139       goto loop;
 140     default:
 141       return SCM_BOOL_F;
 142     }
 143   return SCM_LIST3 (SCM_MAKINUM (a),
 144                     SCM_MAKINUM (o),
 145                     SCM_BOOL(r));
 146 }
 147
 148 static SCM
 149 scm_stand_in_scm_proc(SCM proc)
 150 {
 151   SCM answer;
 152   answer = scm_assoc (proc, scm_stand_in_procs);
 153   if (answer == SCM_BOOL_F)
 154     {
 155       answer = scm_closure (scm_listify (SCM_EOL, SCM_BOOL_F, SCM_UNDEFINED),
 156                             SCM_EOL);
 157       scm_stand_in_procs = scm_cons (scm_cons (proc, answer),
 158                                      scm_stand_in_procs);
 159     }
 160   else
 161     answer = SCM_CDR (answer);
 162   return answer;
 163 }
 164
 165 SCM_DEFINE(scm_procedure_properties, "procedure-properties", 1, 0, 0,
 166            (SCM proc),
 167 "Return @var{obj}'s property list.")
 168 #define FUNC_NAME s_scm_procedure_properties
 169 {
 170   SCM_VALIDATE_PROC(1,proc);
 171   return scm_acons (scm_sym_arity, scm_i_procedure_arity (proc),
 172                     SCM_PROCPROPS (SCM_CLOSUREP (proc)
 173                                    ? proc
 174                                    : scm_stand_in_scm_proc (proc)));
 175 }
 176 #undef FUNC_NAME
 177
 178 SCM_DEFINE(scm_set_procedure_properties_x, "set-procedure-properties!", 2, 0, 0,
 179            (SCM proc, SCM new_val),
 180 "Set @var{obj}'s property list to @var{alist}.")
 181 #define FUNC_NAME s_scm_set_procedure_properties_x
 182 {
 183   if (!SCM_CLOSUREP (proc))
 184     proc = scm_stand_in_scm_proc(proc);
 185   SCM_VALIDATE_CLOSURE(1,proc);
 186   SCM_SETPROCPROPS (proc, new_val);
 187   return SCM_UNSPECIFIED;
 188 }
 189 #undef FUNC_NAME
 190
 191 SCM_DEFINE(scm_procedure_property, "procedure-property", 2, 0, 0,
 192            (SCM p, SCM k),
 193 "Return the property of @var{obj} with name @var{key}.")
 194 #define FUNC_NAME s_scm_procedure_property
 195 {
 196   SCM assoc;
 197   if (k == scm_sym_arity)
 198     {
 199       SCM arity;
 200       SCM_ASSERT (SCM_NFALSEP (arity = scm_i_procedure_arity (p)),
 201                   p, SCM_ARG1, FUNC_NAME);
 202       return arity;
 203     }
 204   SCM_VALIDATE_PROC(1,p);
 205   assoc = scm_sloppy_assq (k,
 206                            SCM_PROCPROPS (SCM_CLOSUREP (p)
 207                                           ? p
 208                                           : scm_stand_in_scm_proc (p)));
 209   return (SCM_NIMP (assoc) ? SCM_CDR (assoc) : SCM_BOOL_F);
 210 }
 211 #undef FUNC_NAME
 212
 213 SCM_DEFINE(scm_set_procedure_property_x, "set-procedure-property!", 3, 0, 0,
 214            (SCM p, SCM k, SCM v),
 215 "In @var{obj}'s property list, set the property named @var{key} to
 216 @var{value}.")
 217 #define FUNC_NAME s_scm_set_procedure_property_x
 218 {
 219   SCM assoc;
 220   if (!SCM_CLOSUREP (p))
 221     p = scm_stand_in_scm_proc(p);
 222   SCM_VALIDATE_CLOSURE(1,p);
 223   if (k == scm_sym_arity)
 224     SCM_MISC_ERROR ("arity is a read-only property", SCM_EOL);
 225   assoc = scm_sloppy_assq (k, SCM_PROCPROPS (p));
 226   if (SCM_NIMP (assoc))
 227     SCM_SETCDR (assoc, v);
 228   else
 229     SCM_SETPROCPROPS (p, scm_acons (k, v, SCM_PROCPROPS (p)));
 230   return SCM_UNSPECIFIED;
 231 }
 232 #undef FUNC_NAME
 233
 234 \f
 235
 236
 237 void
 238 scm_init_procprop ()
 239 {
 240 #include "procprop.x"
 241 }
 242